The use of insects in forensic investigations: An overview on the scope of forensic entomologyIsaac Joseph, Deepu G Mathew, Pradeesh Sathyan, Geetha VargheeseJuly-December 2011, 3(2):89-91DOI:10.4103/0975-1475.92154 PMID:22408328

Forensic entomology is the study of insects/arthropods in criminal investigation. Right from the early stages insects are attracted to the decomposing body and may lay eggs in it. By studying the insect population and the developing larval stages, forensic scientists can estimate the postmortem index, any change in position of the corpse as well as the cause of death. Forensic odontologists are called upon more frequently to collaborate in criminal investigations and hence should be aware of the possibilities that forensic entomology have to offer and use it as an adjunct to the conventional means of forensic investigation.

Background: Sexual dimorphism refers to the differences in size, shape, etc., between males and females. The dentition's use in sex assessment has been explored and advocated owing to its strength and resistance to peri- and post-mortem insults. Objectives: The study evaluated permanent maxillary incisors and canines for sexual dimorphism and estimated the level of accuracy with which they could be used for sex determination. Materials and Methods: The study was conducted on 100 subjects (50 males, 50 females). The mesiodistal dimension of permanent maxillary incisors and canines was measured and the data were subjected to statistical analysis. Result: Univariate analysis revealed that all permanent maxillary incisors and canines exhibited larger mean values of mesiodistal dimension in males compared to females but only canines were found to be statistically significant for sexual dimorphism. Conclusion: The study showed maxillary canines exhibiting significant sexual dimorphism and can be used for sex determination along with other procedures.

Aim: Cheiloscopy is a forensic investigation technique that deals with identification of humans based on lips traces. The aim of this study is to establish the uniqueness of lip prints which aids in personal identification. Materials and Methods: The study group comprised of 200 subjects.The materials used were dark-colored lipstick, paper, cellophane tape, a brush, and a magnifying lens. Results: This study shows that lip prints are unique and permanent for each individual, and the lip prints among family members and between twins revealed different patterns on the whole with few similar grooves suggesting the existence of heredity in the lip prints. Conclusion: Our study showed that lip prints are unique to each individual and can be used for personal identification.

Objective: The aim of the study was to investigate differences in the palatal rugae patterns in males and females of a cross-sectional hospital-based coastal Andhra population and application of discriminant function analysis in sex identification. Materials and Methods: One hundred pre-orthodontic plaster casts, equally distributed between males and females belonging to an age range of 15-30 years, were examined for different rugae patterns. Thomas classification was adopted for analysis. Association between rugae patterns and sexual dimorphism were tested using Unpaired t test, Chi square test and discriminant function analysis developed using SAS package. Results: Difference in unification pattern among males and females was found to be statistically significant. The total number of the rugae was not statistically significant between the sexes. Association between rugae length and shape with sex determination was computed using discriminant analysis which enabled sex differentiation in this population with an accuracy of 78%. Conclusion: Palatal rugae revealed a specific pattern in unification among males and females of the coastal Andhra population. Discriminant function analysis enabled sex determination of individuals. However, these interpretations were precluded by the small sample size and further research work on larger samples and use of different classification systems is required to validate its use in forensic science.

Aim: To analyze efficacy of cellulose acetate film, cellophane tape, and light body impression material in recording enamel rod endings on tooth surface for personal identification. Materials and Methods: Surface enamel rod endings of 30 extracted teeth were recorded from the same area of the same tooth for two times using cellulose acetate film, cellophane tape, and light body impression material. Photomicrographs of enamel rod endings were taken and subjected to Verifinger standard SDK version 5.0 software for analysis. Minutiae scores of all enamel rod end patterns obtained using these three imprint materials were statistically analyzed. Results: Cellulose acetate film imprint showed complete enamel rod end patterns and the software was able to identify the particular tooth with the same previous identification number in subsequent recordings as well. Cellophane tape and light body rubber-base impression material imprint showed incomplete enamel rod end patterns and the software failed to identify the particular tooth with the same previous identification number in subsequent recordings. Statistical analysis revealed that cellulose acetate film recorded more number of minutiae points compared with the other imprint materials. Conclusion: Cellulose acetate film is a reliable material for recording enamel rod endings on tooth surface for personal identification compared with cellophane tape and light body rubber-base impression material.

Objective: The aim of the study is to analyze the knowledge, attitude and practice of forensic odontology among dental practitioners in Chennai. Materials and Methods: A cross-sectional study was conducted in a sample of 322 dental practitioners in Chennai and data was collected by means of a questionnaire. Results: Twenty-one percent of the dental practitioners did not maintain dental records in their clinic/workplace, with only 12% of the practitioners maintaining complete records. Ninety-three percent of dental practitioners were not maintaining dental records for more than seven years. The significance of ante-mortem records in identifying deceased suspects was not known to 17% of the dental practitioners. Forty percent of the dental practitioners were not aware of child abuse and the actions to be taken. Dental age estimation was not known to 41% of the dental practitioners. Thirty-eight percent of the practitioners were unaware of the accurate method of individual identification. About 18% of the dental practitioners did not know the significance of bite mark patterns of the teeth. Ninety-three percent of the practitioners lacked formal training in collecting, evaluating and presenting dental evidence. Thirty percent of dental practitioners did not know they can testify as an expert witness in the court of law. Forty percent of the dental practitioners were unaware of identifying the age and gender of an individual in mass disasters. Conclusion: Our study revealed inadequate knowledge, poor attitude and lack of practice of forensic odontology prevailing among the dental practitioners in Chennai.

Context: Dental remains are usually the last to get destroyed among body parts after death. They may be useful for personal identification in cases of mass disasters and decomposed unidentified bodies. Dental records may help in the identification of suspects in criminal investigations and in medicolegal cases. Maintenance of dental records is legally mandatory in most of the European and American countries. Unfortunately, the law is not very clear in India, and the awareness is very poor. Aims: To assess the awareness regarding the dental record maintenance among dentists in Rajasthan, to deduce the quality of average dental records kept by them and to evaluate the potential use of their maintained records, in any of forensic or medicolegal cases. Settings and Design: A cross-sectional survey was conducted among 100 dental practitioners of different cities in Rajasthan, India. Materials and Methods: Data were collected through a structured questionnaire, which was responded by the study population in the course of a telephonic interview. The questionnaire addressed on the mode of maintaining dental records in their regular practice. Statistical Analysis Used: The data so gathered were subjected for descriptive analysis. Results: As for knowledge or awareness about maintaining dental records, surprisingly a very low percentile (about 38%) of surveyed dentists maintained records. Sixty-two percent of the dentists were maintaining no records at all. Conclusion : Nonmaintenance or poor quality of records maintained indicates that the dentists in Rajasthan are not prepared for any kind of forensic and medicolegal need if it arises.

Objective: The aim of this study is to determine the distribution of different lip print patterns among subjects having different ABO and Rh blood groups and to determine the correlation between their characters and blood groups. Materials and Methods: The present study was done on 150 individuals who were randomly selected and blood groups of these subjects were analyzed. Results: The results revealed no association between distribution of lip print (cheiloscopy) pattern and blood groups. Conclusion: Lip print pattern does not show any correlation between blood groups.

A number of commercial methods for identifying dentures are available. They can be either invasive or noninvasive techniques. The less sophisticated procedures include simple engraving with bur, and more sophisticated procedures use labels or chips. Bar coding system is a way of transferring data to the computer and huge data can be stored as a record. Bar coding can be easily incorporated during acrylization of the denture and thus could be used in individual identification.

Dimensional analysis of various rugae patterns in north Indian population subsetShailja Chatterjee, Mannu KhannaJuly-December 2011, 3(2):86-88DOI:10.4103/0975-1475.92153 PMID:22408327

Introduction: Rugae patterns are significant markers for analyzing anteroposterior changes in adolescence, and forensic investigations. Aim: The purpose of this study was to ascertain the gender-wise predisposition of rugae patterns and to analyze anteroposterior alterations along with any developmental changes in palatal depth. Materials and Methods: One hundred pre-treatment study cast models were obtained from the archives of the Department of Orthodontics, M.M. CDSR, Mullana. Parameters employed were: Division of medial palatal region into "a": Distance between incisive papilla length and anterior limit of the anteriormost rugae; "b": Distance between incisive papilla and most posterior rugae limits; measurement of Lateral rugae dimensions and palatal depth. Statistical analysis: Mean ± S.D. values were obtained and 'P' values calculated. Results: Comparison of "a" and "b" showed a significant difference in the P values between the age-groups 12-13 years and >14 years. Rugae patterns with separate origins showed a predisposition for female gender. Conclusion: A significant change in the anteroposterior medial rugae dimensions was seen in adolescent age groups alongside no variation in palate depth. Hence, it can be concluded that differential growth potential is present in the premaxilla and can cause shift in medial palatal dimensions without altering the rugae patterns and palatal depth.